Analiza i modeliranje fotorazgradnje neonikotinoidnog insekticida u pločastom fotoreaktoru s imobiliziranim slojem fotokatalizatora

master's thesis

• Title (english): Analysis and modeling of photodegradation of neonicotinoid insecticide in a plate photoreactor with an immobilized photocatalyst layer
• Author: Laura Šoić
• Mentor: Vesna Tomašić (mentor)
• Committee member: Vesna Tomašić (predsjednik povjerenstva)
• Committee member: Vanja Gilja (član povjerenstva)
• Committee member: Ljerka Kratofil Krehula (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

U posljednjih nekoliko godina naglo je porasla primjena i proizvodnja pesticida u svijetu. Cilj ovog rada je analiza i modeliranje fotokatalitičke razgradnje neonikotinoidnog insekticida imidakloprida (1-(6-klor-3-piridinilmetil)-N-nitroimidazolidin-2-ilidenamin). Imidakloprid se primjenjuje kao djelatna tvar u brojnim komercijalnim insekticidima s ciljem uništavanja i sprječavanja štetnika usjeva. Fotokatalitička razgradnja provedena je u pločastom fotoreaktoru s recirkulacijom reakcijske smjese uz imobiliziran sloj TiO2 koji je prethodno bio aktiviran djelovanjem UVC zračenja. Za fotoinduciranu razgradnju modelne komponente korištene su dvije komercijalne lampe (Arcadia) koje simuliraju Sunčevo zračenje. Mjerenja su provedena uz konstantnu početnu koncentraciju imidakloprida od 10 ppm. Tijekom provedenih istraživanja ispitan je utjecaj pH (3-9) i protoka aeracije (200 mL/min i 3L/min) na učinkovitost fotokatalitičke razgradnje imidakloprida. Također su provedena dodatna mjerenja u uvjetima bez aeracije. Eksperimentalna mjerenja uključivala su određivanje promjene pH, koncentracije otopljenog kisika u modelnoj otopini te ukupnog organskog ugljika (TOC) na početku te nakon provedene fotokatalitičke razgradnje. Stupanj razgradnje imidakloprida određen je mjerenjem koncentracije imidakloprida prije i nakon provedene reakcije primjenom tekućinske kromatografije visoke učinkovitosti. Dobiveni eksperimentalni podaci testirani su na kinetički model za reakciju pseudo-prvog reda. Rezultati istraživanje pokazali su da je fotokatalitička razgradnja imidakloprida najučinkovitija u kiselim uvjetima rada, tj. pri pH 5 te u uvjetima blizu neutralnog pH, što je izuzetno važno zbog potencijalne primjene ovog procesa u realnim sustavima. Rad u uvjetima aeracije nije pokazao pozitivne učinke na fotokatalitičku razgradnju imidakloprida. U završnom dijelu ispitivanja provedena je kinetička analiza i predložen je odgovarajući kinetički model te su procijenjeni reakcijski parametri, tj. konstanta brzine reakcije, k i korijen srednjeg kvadratnog odstupanja, SD. Postignuto je vrlo dobro slaganje između eksperimentalnih rezultata i pretpostavljenog modela reakcije.

Abstract (english)

In recent years, the use and production of pesticides worldwide has increased sharply. The aim of this work is to analyze and model the photocatalytic degradations of the neonicotinoid insecticide imidacloprid (1-(6-chloro-3-pyridinylmethyl)-N-nitroimidazolidin-2-ylidenamine). Imidacloprid is used as an active substance in a number of commercial insecticides with the aim of destroying and preventing crop pests. Photocatalytic degradation was performed in a plate photoreactor with recirculation of the reaction mixtures with an immobilized TiO2 layer previously activated by UVC radiation. Two-commercial lamps (Arcadia) that simulate solar radiation were used for the photoinduced decomposition of the model component. Measurements were performed at a constant initial imidacloprid concentration of 10 ppm. During the studies, the effect of pH (3-9) and radiation flux (200 mL/min and 3 L/min) on the efficiency of photocatalytic degradation of imidacloprid was examined. Additional measures in radiation-free conditions are also presented. Experimental measurements included determination of changes in pH, dissolved oxygen concentration in the total organic carbon (TOC) model solution at baseline and after photocatalytic degradation. The degree of degradation of imidacloprid was determined by measuring the concentration of imidacloprid before and after the reactions using high performance liquid chromatographs. The obtained experimental data were tested on a kinetic model for the pseudo-first-order reaction. The results showed that photocatalytic degradation of imidacloprid is most effective in acidic operating conditions, i.e at pH 5 and in conditions close to neutral pH, which is extremely important due to the potential applications of this process in real systems. Aeration work did not show positive effects on the photocatalytic degradation of imidacloprid. In the final part of the test, a kinetic analysis was performed and an appropriate kinetic model was proposed, and the reaction parameters, i.e the reaction rate constant, k and the root mean square deviation, SD, were estimated. A very good agreement was reached between the experimental results and the assumed reaction model.

• Keywords: pesticidi; heterogena fotokataliza; imidakloprid; TiO2; pločasti fotoreaktor
• Keywords (english): pesticides; heterogeneous photocatalysis; imidacloprid; TiO2; plate flat photoreactor
• Language: croatian
• URN:NBN: urn:nbn:hr:149:217074
• Project: Number: IP-2018-01-8669; Title: Intenzifikacija fotokatalitičkih i katalitičkih procesa za obradu otpadnih voda i otpadnih plinova; Acronym: IN-PhotoCat; Leader: Vesna Tomašić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2022-04-19 10:58:52